In case of a fresh air system of an internal combustion engine and a crankcase ventilation device of an internal combustion engine it is necessary within the assembly to connect fluid lines to each other or to components of the respective device or installation. For example, a blow-by gas line of the crankcase ventilation device can be fluidically connected to a crankcase of the internal combustion engine or to an air line of the fresh air system or to an oil separator of the crankcase ventilation device. Furthermore, an air line of the fresh air system can be fluidically connected to the filter of the fresh air system or to the charging device of the fresh air system or to a distributor of the fresh air system. In order to establish such fluidic connections as simple as possible, in particular blind, coupling devices of the aforementioned type can be used.
Such a coupling device is known, for example, from WO 2009/124805 A1. It comprises a first connecting piece which has an outer latching contour on its outside and is connected to a first fluid line or can be connected thereto. Furthermore, a second connecting piece is provided which has an outer latching contour on its outside and is connected to a second fluid line or can be connected thereto. Finally, the coupling device also comprises a sleeve into which both connecting pieces can be inserted on opposite ends and which, on its inner side, has two inner latching contours which are complementary to the outer latching contours of the connecting pieces. When inserting the connecting pieces into the sleeve, the inner latching contours latch with the outer latching contours whereby the respective connecting piece is secured in the sleeve against axial withdrawal.
In case of the known coupling device, the respective inner latching contour is implemented by means of a ring-shaped locking element which is inserted into an inner groove formed on the inner side of the sleeve and has radially resilient latching elements.
Further coupling devices are known from EP 1 912 009 A1, EP 0 924 453 A1 and EP 1 835 220 A1.